1. Field of the Invention
The present invention relates to wireless communication and, more particularly, to a method and a device for allocating a resource for an uplink control channel in a wireless communication system.
2. Related Art
A wireless communication system may use a hybrid automatic repeat request (HARQ). The HARQ is a scheme where a transmitter transmits data and then receivers ACK/NACK (acknowledgement/not-acknowledgement) being reception confirmation information with respect to the data, transmits new data or retransmits the transmitted data according to the ACK/NACK.
3GPP (3rd Generation Partnership Project) LTE (long term evolution)/LTE-A (long term evolution-advanced) may transmit the ACK/NACK through a PUCCH (physical uplink control channel) being an uplink control channel. When the ACK/NACK is transmitted through the PUCCH, a resource (PUCCH resource) configuring the PUCCH may be implicitly or explicitly determined. For example, the PUCCH resource may be determined based on a resource occupied by a PDSCH (physical downlink shared channel) being a target of the ACK/NACK response or a control channel scheduling data (transmission block or code-word). Such a PUCCH resource refers to an implicit PUCCH resource. Meanwhile, a case of explicitly indicating and using one or a plurality of resource according to a higher-layer signal refers to an explicit PUCCH resource.
Meanwhile, the number of user equipments (UEs) to be supported by the wireless communication system is increased. Due to this, an existing control channel is expected to be insufficient. In order to solve the problem, introduction of a new control channel is considered.
The new control channel is called an enhanced-physical downlink control channel (E-PDCCH) in an LTE-A. Unlike a PDCCH being an existing control channel is transmitted from a control region of a subframe, the E-PDCCH is transmitted from a data region of a subframe. Further, unlike the PDCCH is decoded based on a cell specific reference signal, the E-PDCCH may be decoded based on a UE specific reference signal.
When the E-PDCCH is introduced, a method of allocating an implicit PUCCH resource for transmitting ACK/NACK according to the related art is necessary to be corrected. This is because the E-PDCCH may be transmitted under a condition different from that of the PDCCH.